This invention relates to continuous molding and more particularly to the continuous molding of objects such as fasteners.
Many objects can be produced by molding. Examples are fasteners set forth and disclosed in U.S. Pat. Nos. 3,103,666; 3,185,367; 3,299,483; 3,399,432; 3,380,122; 3,444,597; 3,457,589; 3,470,834; 3,494,003; 3,650,451; 3,650,452; 3,652,004; 3,659,769; 3,733,657; 3,734,375; 3,759,435; 3,875,648; 3,893,612; 3,895,753; and 3,948,128; 4,039,078 and 4,121,487.
Plastic fasteners in accordance with the foregoing patents have been provided in assemblies of limited length for feeding sequentially through dispensing devices. In U.S. Pat. No. 3,103,666 the fasteners are in clip attached by severable necks to a runner bar. In U.S. Pat. No. 3,875,648 the fasteners are in the form of a stock of continuous side members cross-coupled by a plurality of filaments.
Fastener assemblies employing runner bars are limited in the number of items which can be conveniently supplied in a single assembly. The runners and associated connectors also waste material. While the fastener stock described in U.S. Pat. No. 3,875,648 partially overcomes these limitations, it has proved costly to produce such stock.
The continuous molding of plastic objects such as ribbed film, zipper fasteners, and the like has been proposed in U.S. Pat. Nos. 3,196,196; 3,394,413; 3,439,798; 3,445,915; 3,505,159; 3,509,005; and 3,515,778. However, the methods of these patents are not readily applicable to the molding of many objects, such as fastener stock. The dimensions of many objects are often small. Precision and uniformity are often required for subsequent use, and provision must often be made for clean spaces or "windows". Consistent molding without flash or filming is not easily achieved, and the removal of film raises many difficulties. Thus the removal or defilming of flash with heat as suggested in U.S. Pat. No. 3,509,005 can damage the stock. Skiving with a knife parallel to the axis of rotation is not practical since the knife will be substantially unsupported over the stock and can damage it.
Accordingly, it is an object of the invention to facilitate the continuous molding of objects, particularly plastic fastener stock. A related object is to facilitate the molding of attachment stock with transversely extending filaments.
Further objects of the invention include the improvement of the extrusion process, for example alignment of an extrusion orifice with the surface of a molding wheel, by provision of control over the parameters of the stock, and by alteration of the stock parameters without damage.
Another object of the invention is the provision of stock of consistent quality in rolls or assemblages of any desired length and quantity.
Still another object of the invention is to expedite the formation of fasteners for the attachment of items. A related object is to expedite the formation of assemblages of attachments.
Yet another object of the invention is to facilitate the stretching of continuously molded fasteners. A related object is to facilitate the stretching of continuously molded assemblages of attachments with transverse filaments. Other objects of the invention will become apparent from the description of the invention set forth below.